Method of determining defects in information storage medium, recording/reproducing apparatus using the same, and information storage medium

ABSTRACT

A method of determining whether a defect exists on an information storage medium is provided along with a recording/reproducing apparatus using the same. Such a method comprises: seeking a defect entry whose state information indicates that a defect block or a replacement block has been reinitialized without certification from a defect list for managing an information storage medium and including state information of the defect block and state information of the replacement block, wherein the medium includes a spare area for recording the replacement block to replace the defect block occurring in a user data area on the medium; and certifying the defect block or the replacement block registered in the sought defect entry. As a result, defect information can be effectively rearranged for quick re-initialization without certification in order to improve the performance of a drive system.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims all benefits accruing under 35 U.S.C. §119 fromKorean Patent Application No. 2004-95909, filed on Nov. 22, 2004, in theKorean Intellectual Property Office, the disclosure of which isincorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an information storage medium, and moreparticularly, to a method of determining whether a defect exists on aninformation storage medium, a recording/reproducing apparatus using thesame, and an information storage medium.

2. Related Art

The number of defects on a rewritable information storage mediumincreases due to fingerprints and dust according to use of the medium.Defect blocks occurring during the use of the medium are managed andregistered in a defect information area, and a host or a drive system isinformed of the defect blocks. As a result, a host or a drive systemdoes not allocate data to these defect blocks, and records data only innon-defect blocks. However, when the number of defect blocks increases,a user typically re-initializes the medium.

In specific situations, when the user removes the fingerprints or dustfrom the surface of the medium, the defect blocks registered in thedefect information area may be determined as non-defect blocks through averify-after-write process. If the re-initialization of the rewritableinformation storage medium is necessary, the drive system determineswhether entire blocks in recordable areas on the medium or the defectblocks registered in the defect information area are defect blocksthrough the verify-after-write process.

However, if all the blocks on the medium or the defect blocks registeredin the defect information area are defect blocks through theverify-after-write process, the re-initialization can be very timeintensive, which can inconvenient the user.

Accordingly, there is a need to provide techniques in which defects andpotential defects occurring on an information storage medium can beeffectively managed and re-initialization can be quickly executedwithout a verify-after-write process.

SUMMARY OF THE INVENTION

Various aspects and example embodiments of the present inventionadvantageously provide an information storage medium and arecording/reproducing apparatus equipped with a quick re-initializationof the information storage medium, and a recording/reproducing methodusing the same.

The present invention also provides a method of effectively managinginformation on potential defects in an information storage mediumoccurring due to a quick re-initialization operation without averify-after-write process, and a recording/reproducing apparatus usingthe same.

According to an aspect of the present invention, there is provided amethod of determining whether defects exist in an information storagemedium having a data area including a user data area for recording dataand a spare area for recording a replacement block to replace a defectblock occurring in the user data area. Such a method comprises: seekinga defect entry whose state information indicates that a defect block ora replacement block has been re-initialized without certification, froma defect list for managing the medium and including state information ofthe defect block and state information of the replacement block; andcertifying the defect block or the replacement block registered in thesought defect entry.

The method may further comprise: deleting the defect entry whose stateinformation indicates that the defect block or the replacement block hasbeen re-initialized without certification from the defect list as aresult of the certification.

State information indicating that a corresponding block is a defectableblock may be further included in the defect entry whose stateinformation indicates that the defect block or the replacement block hasbeen reinitialized without certification. The certifying may comprise:deleting the defect entry from the defect list, if no defect exists inthe defectable block as a result of the certification of the defectableblock; and generating a defect entry whose state information indicatesthat the corresponding block is a defect block, if a defect exists inthe defectable block as the result of the certification of thedefectable block, wherein state information indicating that the defectblock or the replacement block has been reinitialized withoutcertification is not set in the defect entry.

State information indicating that a corresponding replacement block isan available replacement block or state information indicating that thecorresponding replacement block is an unavailable replacement block maybe further included in the defect entry whose state informationindicates that the defect block or the replacement block has beenre-initialized without certification. The certifying may comprise:generating a defect entry whose state information indicates that thecorresponding replacement block is an available replacement block, if nodefect exists in the corresponding replacement block as a result of thecertification of the corresponding replacement block, wherein stateinformation indicating that the defect block or the replacement blockhas been re-initialized without certification is not set in the defectentry; and generating a defect entry whose state information indicatesthat the corresponding replacement block is an unavailable replacementblock, if a defect exists in the corresponding replacement block as theresult of the certification of the corresponding replacement block,wherein state information indicating that the defect block or thereplacement block has been re-initialized without certification is notset in the defect entry.

According to another aspect of the present invention, there is provideda recording/reproducing apparatus comprising: a write/read unit torecord data on an information storage medium and reading data from themedium; and a control unit arranged to control the write/read unit toread a defect list including state information of a defect block andstate information of a replacement block in order to manage the mediumincluding a spare area for recording the replacement block to replacethe defect block occurring in a user data area on the medium, to seek adefect entry whose state information indicates that the defect block orthe replacement block has been re-initialized without certification, andto certify the defect block or the replacement block registered in thedefect entry.

The control unit may delete the defect entry whose state informationindicates that the defect block or the replacement block has beenre-initialized without certification from the defect list as a result ofthe certification.

According to another aspect of the present invention, there is providedan information storage medium having recorded thereon a defect listincluding state information of a defect block and state information of areplacement block in order to manage the medium including a spare arearecording for the replacement block to replace the defect blockoccurring in a user data area on the medium, and in which the defectblock or the replacement block registered in a defect entry whose stateinformation indicates that the defect block or the replacement block hasbeen re-initialized without certification is certified in acertification operation of the medium.

The defect entry whose state information indicates that the defect blockor the replacement block has been re-initialized without certificationmay be deleted from the defect list as a result of the certification.

In addition to the example embodiments and aspects as described above,further aspects and embodiments of the present invention will beapparent by reference to the drawings and by study of the followingdescriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention will become apparentfrom the following detailed description of example embodiments and theclaims when read in connection with the accompanying drawings, allforming a part of the disclosure of this invention. While the followingwritten and illustrated disclosure focuses on disclosing exampleembodiments of the invention, it should be clearly understood that thesame is by way of illustration and example only and that the inventionis not limited thereto. The spirit and scope of the present inventionare limited only by the terms of the appended claims. The followingrepresents brief descriptions of the drawings, wherein:

FIG. 1 is a schematic block diagram of an example recording/reproducingapparatus according to an embodiment of the present invention;

FIG. 2 is a structural diagram of an example information storage mediumthat is a single layer disk according to an embodiment of the presentinvention;

FIG. 3 is a structural diagram of an example information storage mediumthat is a double layer disk according to an embodiment of the presentinvention;

FIG. 4 is a structural diagram of a defect list according to anembodiment of the present invention;

FIG. 5 is a structural diagram of a DFL entry shown in FIG. 4;

FIG. 6 is an illustrative diagram of state information of the DFL entryshown in FIG. 5;

FIGS. 7A and 7B are illustrative diagrams of a method of processing DFLentries with respect to blocks in a spare area newly allocated due todisk re-initialization according to an embodiment of the presentinvention;

FIG. 8A is a diagram of state information of a defect list just before anew spare area is allocated according to an embodiment of the presentinvention in a state illustrated in FIG. 7A, and FIG. 8B is a diagram ofstate information of the defect list just after the new spare area isallocated in a state illustrated in FIG. 7B;

FIGS. 9A and 9B are illustrative diagrams of a method of processing DFLentries with respect to blocks in spare areas newly allocated due todisk re-initialization according to an embodiment of the presentinvention;

FIG. 10A is a diagram of state information of a defect list just beforenew spare areas are allocated according to an embodiment of the presentinvention in a state illustrated in FIG. 9A, and FIG. 10B is a diagramof state information of the defect list just after the new spare areasare allocated in a state illustrated in FIG. 9B;

FIG. 11A is an illustrative diagram of a state of blocks in which secondstate information is set to “1” according to an embodiment of thepresent invention;

FIG. 11B is an illustrative diagram of a state in which two defectblocks and a replacement block are further generated in the stateillustrated in FIG. 11A;

FIG. 12A is an example of entries indicating state information of theblocks in the state illustrated in FIG. 11B;

FIG. 12B is an illustrative diagram of a state in which entries arearranged using a verify-after-write process according to an embodimentof the present invention; and

FIG. 13 is a flowchart illustrating procedures of a verify-after-writeoperation according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will now be described in detailwith reference to the accompanying drawings.

Turning now to FIG. 1, a schematic block diagram of an examplerecording/reproducing apparatus according to an embodiment of thepresent invention is illustrated. Referring to FIG. 1, therecording/reproducing apparatus includes a write/read unit 2 and acontrol unit 1. For purposes of brevity, the recording/reproducingapparatus, albeit in whole or in part, can also be referred to as adrive system which can be internal (housed within a host 3) or external(housed in a separate box that connects to a host 3, as shown in FIG.1). An information storage medium can be any rewritable optical disc,such as DVD-RW, DVD+RW, CD-RW and other high density disc, such asblue-ray disc (BD) and advanced optical disc (AOD). However, otherstorage media can also be utilized, including DVD, DVD-R, DVD-RAM,DVD-ROM, CD, CD-R, and CD-ROM. In addition, such a recording/reproducingapparatus may be a single apparatus, or may be separated into arecording apparatus (i.e., digital video disc recorder “DVDR”) and areading apparatus (i.e., compact disc player “CDP” or digital video discplayer “DVDP”).

The write/read unit 2 records data on a disk 100, which is aninformation storage medium according to the present embodiment, andreads the recorded data by using an optical pickup (not shown).

The controller 1 controls the write/read unit 2 to record data on thedisk 100 and read data from the disk 100 according to a predeterminedfile system. In particular, according to embodiments of the presentinvention, the control unit 1 allocates a new spare area for diskre-initialization and manages state information of defect blocks in auser data area and state information of replacement blocks in the newspare area.

The control unit 1 includes a system controller 10, a host interface(I/F) 20, a digital signal processor (DSP) 30, a radio frequencyamplifier (RF AMP) 40, and a servo 50.

In a recording operation, the host I/F 20 receives a predetermined writecommand from a host 3 and transmits the write command to the systemcontroller 10. The system controller 10 controls the DSP 30 and theservo 50 in order to perform the write command received from the hostI/F 20. The DSP 30 adds additional data, such as, parity bits for errorcorrection to data to be recorded which is received from the host I/F20, generates an error correction code (ECC) block, which is an errorcorrection block, by performing ECC encoding on the data, and modulatesthe generated ECC block in a predetermined manner. The RF AMP 40converts the data output from the DSP 30 to an RF signal. The write/readunit 2 including an optical pickup (not shown) records the RF signaloutput from the RF AMP 40 on the disk 100. The servo 50 receives acommand required for a servo control from the system controller 10 andservo-controls the optical pickup included in the write/read unit 2.

In particular, according to the embodiments of the present invention,the system controller 10 manages defect states of blocks when a newspare area is allocated on the disk 100 for disk re-initialization.

If the system controller 10 determines that a physical address of adefect block in a user data area on the disk 100 before the diskre-initialization is still included in the user data area afterallocation of a new spare area on the disk 100, the system controller 10controls the write/read unit 2 to record a defect list (DFL) entryhaving state information indicating that the defect block isre-initialized and is a defectable block instead of a DFL entry for thedefect block.

If the system controller 10 determines that a physical address of thedefect block in a user data area on the disk 100 before the diskre-initialization is included in a physical address of a replacementblock in a new spare area after allocation of the new spare area on thedisk 100, the system controller 10 controls the write/read unit 2 torecord a DFL entry having state information indicating that thereplacement block is re-initialized and is an unavailable replacementblock (i.e., a replacement block that cannot be used for replacement)instead of a DFL entry for the replacement block.

If the system controller 10 determines that a physical address of anunavailable replacement block in the spare area on the disk 100 beforethe disk re-initialization is included in a physical address of a userdata area after allocation of a new spare area on the disk 100, thesystem controller 10 controls the write/read unit 2 to record a DFLentry having state information indicating that the defect block isre-initialized and is a defectable block instead of a DFL entry for thedefect block. Since the replacement block is in the spare area beforethe disk re-initialization, and after the disk re-initialization, thereplacement block belongs to the user data area, the replacement blockis referred to “defect block.” The DFL entry and state information willbe described in detail later.

When a certification is partially or fully performed for the disk 4, thesystem controller 10 certifies blocks registered in DFL entries havingdefect information generated in response to a quick re-initializationperformed without certification, i.e., state information indicating thatre-initialization without certification has been performed, and deletesthe DFL entries whose state information indicates that re-initializationwithout certification has been performed.

In detail, when state information indicating that a corresponding blockis a defectable block is further included in the state informationindicating that re-initialization without certification has beenperformed, if no defect exists in the defectable block as a result ofthe certification of the defectable block, the system controller 10deletes a corresponding DFL entry from a defect list. However, if adefect exists in the defectable block as a result of the certificationof the defectable block, the system controller 10 generates a DFL entrywhose the state information indicates that the corresponding block is adefect block, wherein the state information indicating thatre-initialization without certification has been performed is not set inthe DFL entry.

When state information indicating that a corresponding replacement blockis an available replacement block (i.e., a block that can be used forreplacement) or state information indicating that the correspondingreplacement block is an unavailable replacement block is furtherincluded in the state information indicating that re-initializationwithout certification has been performed, if no defect exists in thecorresponding replacement block as a result of the certification of thecorresponding replacement block, the system controller 10 generates aDFL entry whose state information indicates that the correspondingreplacement block is an unavailable replacement block, wherein the stateinformation indicating that re-initialization without certification hasbeen performed is not set in the DFL entry. However, if a defect existsin the corresponding replacement block as a result of the certificationof the corresponding replacement block, the system controller 10generates a DFL entry whose state information indicates that thecorresponding replacement block is an available replacement block,wherein the state information indicating that re-initialization withoutcertification has been performed is not set in the DFL entry.

In a reproduction operation, after the host I/F 20 receives areproduction command from the host 3, the system controller 10 performsinitialization for data reproduction. The write/read unit 2 radiates alaser beam, via the optical pickup, on the disk 100 and outputs anoptical signal obtained by receiving the laser beam reflected from thedisk 100. The RFAMP 40 converts the optical signal output from thewrite/read unit 2 to an RF signal, provides modulated data obtained fromthe RF signal to the DSP 30, and provides a servo control signalobtained from the RF signal to the servo 50. The DSP 30 demodulates themodulated data and outputs data obtained through ECC error correction.The servo 50 servo controls the optical pickup based on the servocontrol signal received from the RF AMP 40 and the command required forthe servo control received from the system controller 10. Then, the hostI/F 20 transmits data received from the DSP 30 to the host 3.

A structure of an example information storage medium according toembodiments of the present invention will now be described withreference to FIG. 2 and FIG. 3 herein below.

FIG. 2 is a structural diagram of an example information storage mediumthat is a single layer disk according to an embodiment of the presentinvention. Referring to FIG. 2, the disk 100 includes a lead-in area 110located in an inner circumference of the disk 100, a lead-out area 120located in an outer circumference of the disk 100, and a data area 130located in an intermediate portion between the lead-in area 110 and thelead-out area 120 in a disk radius direction where user data isrecorded.

The lead-in area 110 includes a defect management area (DMA) #2, arecording condition test area, and a DMA #1. The data area 130 includesa spare area #1, a user data area, and a spare area #2. The lead-outarea 120 includes a DMA #3 and a DMA #4.

Each DMA is used to store defect management information for rewritableinformation storage media, and is typically located in either thelead-in area 110 or the lead-out area 130 of the disk 100.

When the disk 100 is initialized, a drive manufacturer or a user can setthe sizes of spare areas in the data area 130 wherein replacement blocksfor replacing defect blocks due to defects generated in predeterminedportions of the user data area are to be recorded. The drivemanufacturer or user can also decide whether to allocate the spare areasin the data area 130 or other areas on the disk 100. If it is necessaryto reinitialize the disk, spare areas can be newly allocated on the disk100.

Defect management information recorded in the DMAs may include a defectlist (DFL) for defect information and a disk definition structure (DDS)including information on a structure of the data area 130 on the disk100.

The defect list (DFL) is typically comprised of a DFL header and DFLentries. A structure of an example defect list (DFL) will be describedin detail with reference to FIG. 4.

The recording condition test area is an area provided for performingoptimum power control (OPC) procedure, that is, a test with variouswrite powers based on write strategies to determine an optimal writepower and write variables for the disk 100 and the recording/reproducingapparatus in combination.

FIG. 3 is a structural diagram of an example information storage mediumthat is a double layer disk according to an embodiment of the presentinvention. However, a disk 100 having two or more recording layers canalso be shown in the same manner.

Referring to FIG. 3, the disk 100 includes two recording layers L0 andL1. Specifically, a recording layer L0 includes a lead-in area #0 110, adata area #0 130, and a lead-out area #0 120. Similarly, a recordinglayer #1 also includes a lead-in area #1 110, a data area #1 130, and alead-out area #1 120.

The lead-in area #0 110 of the recording layer L0 includes a DMA#1, arecording condition test area #0, and a DMA#2; the data area #0 130 ofthe recording layer L0 includes a spare area #1, a user data area #0,and a spare area #2; and the lead-out area #0 120 of the recording layerL0 includes a DMA #3 and a DMA #4.

Similarly, the lead-in area #1 110 of the recording layer L1 includes aDMA#1, a recording condition test area #1, and a DMA#2; the data area #1130 of the recording layer L1 includes a spare area #3, a user data area#1, and a spare area #4; and the lead-out area #1 120B of the recordinglayer L1 includes a DMA #3 and a DMA #4.

Turning now to FIG. 4, an example data format of a defect list (DFL) 400according to an embodiment of the present invention is illustrated.Referring to FIG. 4, the DFL 400 includes a DFL header 410, which is apart to record number information for defect management of blocks, and aDFL entry list 420, which is a list of DFL entries. For purposes ofbrevity, the DFL entry is referred to as a defect entry herein.

The DFL header 410 includes information on a DFL identifier 411, thenumber of defect blocks having a replacement block 412, the number ofdefect blocks not having a replacement block 413, the number ofavailable spare blocks 414, the number of unavailable spare blocks 415,and the number of defectable blocks 416.

The number of defect blocks having a replacement block 412 representsthe number of DFL entries having defect state information indicatingthat a defect block has been replaced with a replacement block in aspare area on the disk 100.

The number of defect blocks not having a replacement block 413represents the number of DFL entries having defect state informationindicating a defect block, which does not have a replacement block inthe spare area on the disk 100.

The number of available spare blocks 414 represents the number of DFLentries having defect state information indicating a block which can beused for replacement, among unreplaced blocks in the spare area on thedisk 100.

The number of unavailable spare blocks 415 represents the number of DFLentries having defect state information indicating a block which cannotbe used for replacement, among the unreplaced blocks in the spare areaon the disk 100.

The number of defectable blocks 416 represents the number of DFL entrieshaving defect state information indicating a block susceptible of beinga defect block but which has not been certified yet from among blocks ina user data area on the disk 100.

The DFL entry list 420, which is a set of DFL entries having defectstate information on blocks, includes a DFL entry #1 421, a DFL entry #2422 . . . and a DFL entry #N 423.

FIG. 5 illustrates an example data format of a DFL entry #i 500illustrated in FIG. 4.

Referring to FIG. 5, the DFL entry #i 500 includes first stateinformation 510, a physical address of a defect block 520, second stateinformation 530, and a physical address of a replacement block 540.

The first state information 510 includes information on defect states ofdefect blocks in the user data area on the disk 100 and information onstates indicating whether replacement blocks in the spare area areavailable on the disk 100. The first state information 510 will bedescribed in detail later with reference to FIG. 6.

The second state information 530 includes information on statesindicating whether blocks are re-initialized. Quick re-initializationcan be achieved by indicating only information indicating thatre-initialization has been performed in the second state information 530of the DFL entry #i 500 without performing a verify-after-write processin the re-initialization. In addition, when data is recorded after there-initialization, if second state information 530 of a DFL entry 421,422 or 423, as shown in FIG. 4, for a block to be recorded is set tostate information indicating that re-initialization has been performed,a drive system, i.e., a recording/reproducing apparatus, as shown inFIG. 1, recognizes this state; as a result, even if a host 3 commandsthe drive system to record data in a portion of the block, the drivesystem can record the data by padding predetermined data in theremaining portion of the block without an additional read-modify-writeprocess. When a reproduction command of a block is received from thehost 3, as shown in FIG. 1, if second state information 530 is set tostate information indicating that re-initialization has been performed,and since the drive system recognizes that data recorded in the block ismeaningless, the drive system can transmit null data or a check messageto the host 3 with no delay.

The physical address of a defect block 520 is a physical address atwhich the defect block is located in the user data area on the disk 100,and the physical address of a replacement block 540 is a physicaladdress at which the replacement block is located in the spare area onthe disk 100.

FIG. 6 is an illustrative diagram of the first state information 510 ofthe DFL entry #i 500 illustrated in FIG. 5.

Referring to FIG. 6, the first state information 510 has five stateinformation values “1,” “2,” “3,” “4”, and “5”.

The state information value “1” indicates a state of a defect blockhaving a replacement block. In this case, a physical address of thedefect block exists in the user data area on the disk 100, and aphysical address of the replacement block replacing the defect blockexists in the spare area on the disk 100.

The state information value “2” indicates a state of a defect block nothaving a replacement block. In this case, a physical address of thedefect block exists in the user data area on the disk 100.

The state information value “3” indicates a state of a defectable block.The defectable block indicates a block that might be a defect blockwhich has not been certified yet through an error-correction-after-writeprocess. Thus, the defectable block has to be certified through theerror-correction-after-write process at a later time when large RF orservo signals are detected in a process of certifying or scanning a disk100. In this case, a physical address of the defectable block indicatesa physical address of a block that might be a defect block which has notbeen certified yet.

The state information value “4” indicates a state of a replacement blockindicating an available replacement block in the spare area on the disk100. In this case, a physical address of the replacement block indicatesa physical address of an available block among unreplaced blocks in thespare area on the disk 100.

The state information value “5” indicates a state of a replacement blockindicating an unavailable replacement block in the spare area on thedisk 100. In this case, a physical address of the replacement blockindicates a physical address of an unavailable block among theunreplaced blocks in the spare area on the disk 100.

The state information values “1,” “2,” and “3” indicate states of blocksin the user data area on the disk 100, and the state information values“4” and “5” indicate states of blocks in the spare area on the disk 100.

While the second state information 530 is not shown in FIG. 6, forexample, if the second state information 530 is set to “1,” thisindicates that re-initialization of a corresponding block has beenperformed, and if the second state information 530 is set to “0,” thisindicates that this block has not been reinitialized or has been usedagain after re-initialization. In addition, if the second stateinformation 530 is set to “0,” this indicates that valid data is storedin the block, and if the second state information 530 is set to “1,”this indicates that valid data is not stored in the block since theblock has been re-initialized.

FIGS. 7A and 7B are illustrative diagrams of a method of processing DFLentries with respect to blocks in a spare area newly allocated in a dataarea on a disk due to disk re-initialization, according to an embodimentof the present invention.

FIG. 7A illustrates states of data blocks in an information storagemedium that is a single layer disk 100, as shown in FIG. 2, in which aspare area #1 is allocated before the disk re-initialization, and FIG.7B illustrates states of the data blocks in the disk 100 in which thespare area #1 is newly allocated on the disk 100 after the diskre-initialization.

Referring to FIG. 7A, a data area 130 includes at least a spare area #1and a user data area. Blocks (1), (2) and (3) are recorded in an endportion of the user data area. Block (1) is a defect block, which has areplacement block for replacing the defect block. Block (2) is a defectblock, which does not have a replacement block for replacing the defectblock. Block (3) is a defectable block.

In this state, when the new spare area #1 is allocated in a data area130 on the disk 100 due to the disk re-initialization during the use ofthe disk 100, states of the blocks (1), (2) and (3), which still existin the user data area after the disk re-initialization, are shown inFIG. 7B.

Referring to FIG. 7B, DFL entries with respect to the block (1) having areplacement block, the block (2) not having a replacement block, and thedefectable block (3) are changed to DFL entries having state informationindicating that these blocks have been re-initialized withoutcertification and state information indicating that these blocks aredefectable blocks.

FIG. 8A is a diagram of state information of a defect list 420, asshown, for example, in FIG. 4, including DFL entries just beforere-initialization, that is, before a new spare area is allocated in adata area 130 on the disk 100 according to an embodiment of the presentinvention in a state illustrated in FIG. 7A, and FIG. 8B is a diagram ofstate information of the defect list 420 including DFL entries justafter re-initialization, that is, after the new spare area is allocatedin a data area 130 on the disk 100 in a state illustrated in FIG. 7B.

Referring to FIG. 8A, a DFL entry for the block (1) is the first entryshown in FIG. 8A. Since block (1) is a defect block having a replacementblock, its first state information 510, as shown, for example, in FIG.5, is set to “1,” and since a physical address of the defect block 520is “0010000h” and the defect block is not re-initialized, its secondstate information 530 is set to “0.” Since block (2) is a defect blocknot having a replacement block, its first state information 510 is setto “2,” and since a physical address of the defect block 520 is“0010100h” and the defect block is not re-initialized, its second stateinformation 530 is set to “0.” Since block (3) is a defectable block,its first state information 510 is set to “3,” and since a physicaladdress of the defect block 520 is “0010110h” and the defect block isnot re-initialized, its second state information 530 is set to “0.”

A DFL entry list (defect list) 420 shown in FIG. 8A is changed to a DFLentry list 420 shown in FIG. 8B by the re-initialization in which thespare area is newly allocated in a data area 130 on the disk 100.

Referring to FIG. 8B, the DFL entry for the block (1) is the first entryshown in FIG. 8B, a DFL entry for the block (2) is the second entry, anda DFL entry for the block (3) is the third entry. For each of the DFLentries for the blocks (1), (2) and (3), first state information 510 isset to “3” indicating a defectable block due to the re-initialization,and second state information 530 indicating whether to be re-initializedis set to “1” indicating that re-initialization has been performed.

Likewise, since a defect block in the user data area on the disk 100after disk re-initialization is a defectable block, when data isrecorded at a later time, it is preferable to certify if the block is adefectable block by performing a verify-after-write process.

After second state information 530 of a DFL entry is set to “1”indicating that re-initialization has been performed due to there-initialization, if a corresponding block is used again, the secondstate information 530 should be set to “0.” The second state information530 due to the re-initialization is set to “1” to indicate that datarecorded in a corresponding block is not valid any more due to there-initialization.

FIGS. 9A and 9B are illustrative diagrams of a method of processing DFLentries with respect to blocks in spare areas newly allocated on a disk100 due to disk re-initialization according to an embodiment of thepresent invention.

FIG. 9A illustrates states of data blocks in an information storagemedium that is a single layer disk, as shown in FIG. 2, in which a sparearea #1 is allocated before the disk re-initialization, and FIG. 9Billustrates states of the data blocks in the disk 100 in which spareareas #1 and #2 are newly allocated on the disk 100 after the diskre-initialization.

Referring to FIG. 9A, a data area 130 includes a spare area #1 and auser data area. As shown in FIG. 9A, only the spare area #1 is allocatedon the disk 100. Blocks (4), (5) and (6) are recorded in an end portionof the user data area, and block (7) is recorded in the spare area #1 onthe disk 100. Block (4) is a defect block, which has a replacement blockfor replacing the defect block. Block (5) is a defect block, which doesnot have a replacement block for replacing the defect block. Block (6)is a defectable block. Block (7) is a replacement block in the sparearea #1, which cannot be used for replacement.

In this state, due to the disk re-initialization during the use of thedisk 100, since the new spare area #1 is reductively allocated, block(7) existed in the spare area #1 before the states of there-initialization is included in the user data area after there-initialization, and since the spare area #2 is newly allocated in adata area 130 on the disk 100, blocks (4), (5) and (6) existed in theuser data area before the re-initialization are all included in thespare area #2 after the re-initialization. These states are shown inFIG. 9B.

Referring to FIG. 9B, if the defect blocks (4), (5) and (6) in the userdata area on the disk 100 before the re-initialization is included inthe spare area #2 due to the re-initialization, DFL entries for theblocks (4), (5) and (6) are changed to DFL entries having stateinformation indicating that all the blocks are re-initialized withoutcertification and state information indicating that they cannot be usedfor replacement. Also, if the replacement block (7) in the spare area #1on the disk 100 before the re-initialization is included in the userdata area due to the re-initialization, a DFL entry for the block (7) ischanged to a DFL entry having state information indicating that theblock (7) is re-initialized without certification and state informationindicating that the block (7) is a defectable block.

FIG. 10A is a diagram of state information of a defect list 420including DFL entries just before re-initialization, that is, before newspare areas are allocated in the data area 130 on the disk 100 accordingto an embodiment of the present invention in a state illustrated in FIG.9A, and FIG. 10B is a diagram of state information of the defect list420 including DFL entries just after re-initialization, that is, beforethe new spare areas are allocated in the data area 130 on the disk 100in a state illustrated in FIG. 9B.

Referring to FIG. 10A, a DFL entry for the block (4) is the first entryshown in FIG. 10A. Since the block (4) is a defect block having areplacement block, its first state information 510, as shown, forexample, in FIG. 5, is set to “1,” and since a physical address of thedefect block 520 is “0010000h” and the defect block is notre-initialized, its second state information 530 is set to “0.” Sincethe block (5) is a defect block not having a replacement block, itsfirst state information 510 is set to “2,” and since a physical addressof the defect block 520 is “0010100h” and the defect block is notre-initialized, its second state information 530 is set to “0.” Sincethe block (6) is a defectable block, its first state information 510 isset to “3,” and since a physical address of the defect block 520 is“0010110h” and the defect block is not re-initialized, its second stateinformation 530 is set to “0.” Since the block (7) is an unavailablereplacement block, its first state information 510 is set to “5,” andsince a physical address of the defect block 520 is “0100000h” and thedefect block is not re-initialized, its second state information 530 isset to “0.”

A DFL entry list (defect list) 420 shown in FIG. 10A is changed to a DFLentry list (defect list) 420 shown in FIG. 10B by the re-initializationin which the spare areas are newly allocated in a data area 130 on thedisk 100.

Referring to FIG. 10B, the DFL entry for the block (4) is the secondentry shown in FIG. 10B, a DFL entry for the block (5) is the thirdentry shown in FIG. 10B, a DFL entry for the block (6) is the fourthentry shown in FIG. 10B, and a DFL entry for the block (7) is the firstentry shown in FIG. 10B. For each of the DFL entries for the blocks (4),(5) and (6), first state information 510 is set to “5” indicating anavailable replacement block due to the re-initialization, second stateinformation 530 indicating whether to be re-initialized is set to “1”indicating that re-initialization has been performed, and a physicaladdress of each defect block 520 is changed to a location of a physicaladdress of a replacement block 540. For the DFL entry for the block (7),first state information 510 is set to “3” indicating a defectable blockdue to the re-initialization, second state information 530 indicatingwhether to be reinitialized is set to “1” indicating thatre-initialization has been performed, and a physical address of areplacement block 540 is changed to a location of a physical address ofa defect block 520.

While the above methods are described in connection with an informationstorage medium that is a single layer disk 100, as shown in FIG. 2, suchmethods can also be applied to an information storage medium that is adouble layer disk 100, as shown in FIG. 3, or even disk 100 havingmultiple recording layers.

As described above, a change of a defect list 420 without certificationmakes the defect list 420 have state information indicating thatre-initialization without certification has been performed according toa method of re-initializing a rewritable information storage medium.Re-initialization without certification can be performed from time totime when quick re-initialization is needed, since it takes a relativelylong time to perform the certification. Due to the quickre-initialization, blocks registered in a defect list 420 due to defectsare stored in the defect list 420 as DFL entries having stateinformation indicating that the blocks are not certified, that theblocks should be certified in the future, or that the blocks aredefectable blocks, i.e., DFL entries in which second state information530 is set. Thus when the blocks are used in the future, it is finallydetermined whether they are defect blocks according to the stateinformation. That is, the quick re-initialization method improves thetime efficiency by dividing the time for certification into periods oftime of using each block.

A full or partial certification method with respect to the defectinformation is required in conjunction with the use of new defectinformation.

Thus, to clear off the defect information due to the re-initializationwithout certification according to an embodiment of the presentinvention, blocks having the defect information are certified using thefull or partial certification method, so that the defect information canbe removed from the defect list 420.

The full certification method is a method of certifying all the blocksin the user data area on the disk 100, and the partial certificationmethod is a method of certifying some of all the blocks in the user dataarea on the disk 100. As an example of the partial certification method,only blocks, which are defectable blocks or defect blocks, in the defectlist 420 are certified. By doing this, the certification can beperformed in a relatively quick time. As an example of the fullcertification method, the entire user data area is certified using theverify-after-write process, it is determined whether each block is adefect block, and the determination result is reflected on the defectlist 420.

A certification method according to an embodiment of the presentinvention will now be described herein below.

FIG. 11A is an illustrative diagram of a state of blocks in which secondstate information 530 is set to “1” according to an embodiment of thepresent invention.

Referring to FIG. 11A, block (a) is a defect block, which does not havea replacement block, in a user data area included in a data area 130 onthe disk 100. Block (b) is a defectable block in the user data areaincluded in a data area 130 on the disk 100. Block (c) is an availablespare area block in a spare area #2 included in a data area 130 on thedisk 100. In addition, block (d) is an unavailable spare area block inthe spare area #2 included in a data area 130 on the disk 100.

For example, a disk 100 having a state illustrated in FIG. 11A rightafter disk re-initialization can be a state illustrated in FIG. 11B dueto use of the disk 100.

FIG. 11B is an illustrative diagram of a state in which two defectblocks and a replacement block are further generated in the stateillustrated in FIG. 11A.

Referring to FIG. 11B, a defect block (e) is generated in the user dataarea included in a data area 130 on the disk 100. A replacement block(e)′ replacing the defect block (e) is generated in the spare area #2included in a data area 130 on the disk 100. In addition, a defect block(f) not having a replacement block, indicating that a block is generatedbut not replaced yet, is generated in the user data area in a data area130 on the disk 100.

FIG. 12A is an example of entries indicating state information of theblocks in the state illustrated in FIG. 11B.

Referring to FIG. 12A, first four defect entries on a defect list 420indicate DFL entries generated due to disk re-initialization, and nexttwo defect entries on the defect list 420 indicate DFL entries generatedduring use of the disk 100.

For the first defect entry related to the defect block (a), which doesnot have a replacement block and exists in the user data area, its firststate information 510 is set to “2” to indicate a state of a defectblock not having a replacement block, and its second state information530 is set to “1” to indicate that re-initialization withoutcertification has been performed.

For the second defect entry related to the defectable block (b) existingin the user data area, its first state information 510 is set to “3” toindicate a defectable state, and its second state information 530 is setto “1” to indicate that re-initialization without certification has beenperformed.

For the third defect entry related to the available spare area block (c)existing in the spare area #2, its first state information 510 is set to“4” to indicate an available state, and its second state information 530is set to “1” to indicate that re-initialization without certificationhas been performed.

For the fourth defect entry related to the unavailable spare area block(d) existing in the spare area #2, its first state information 510 isset to “5” to indicate an unavailable state, and its second stateinformation 530 is set to “1” to indicate that re-initialization withoutcertification has been performed.

For the fifth defect entry related to the defect block (e), which has areplacement block and exists in the user data area, its first stateinformation 510 is set to “1” to indicate a state of a defect blockhaving a replacement block, and its second state information 530 is setto “0” since re-initialization without certification has not beenperformed.

For the sixth defect entry related to the defect block (f), which doesnot have a replacement block and exists in the user data area, its firststate information 510 is set to “2” to indicate a state of a defectblock not having a replacement block, and its second state information530 is set to “0” since re-initialization without certification has notbeen performed.

In this state, objects to perform the verify-after-write processaccording to an embodiment of the present invention are the first fourentries whose second state information 530 is set to “1.”

FIG. 12B is an illustrative diagram of a state in which the entries arearranged using the verify-after-write process according to an embodimentof the present invention.

Referring to FIG. 12B, for the first defect entry, if block (a) iscertified and determined as a defect block, its first state information510 is set to “2” to indicate a state of a defect block not having areplacement block, and its second state information 530 is set to “0”since the certification has been performed.

For the second defect entry, if block (b) is certified and determined asa non-defect block, the entry for the block (b) is deleted from thedefect list 420 since the block (b) is an available block with nodefect, which exists in the user data area included in a data area 130on the disk 100.

For the third defect entry, if block (c) is certified and determined asa non-defect block, its first state information 510 is set to “4” toindicate an available state, and its second state information 530 is setto “0” since the certification has been performed.

For the fourth defect entry, if block (d) is certified and determined asa defect block, its first state information 510 is set to “5” toindicate an unavailable state, and its second state information 530 isset to “0” since the certification has been performed.

As a result, due to the verify-after-write process, all defect entrieswhose second state information 530 is set to “1” indicating thatre-initialization without certification has been performed disappearfrom the defect list 420.

FIG. 13 is a flowchart illustrating procedures of a verify-after-writeoperation according to an embodiment of the present invention.

A drive system (i.e., a recording/reproducing apparatus, as shown inFIG. 1) receives a verify-after-write command from a host 3, as shown,for example, in FIG. 1, in operation 1310.

The drive system reads a defect list 420 recorded on an informationstorage medium such as a single layer disk 100, as shown, for example,in FIG. 2, or alternatively, a double layer disk 100, as shown, in FIG.3, and stores the read defect list 420 in a memory at operation 1320.

The drive system seeks DFL entries whose second state information 530,as shown, for example, in FIG. 5, is set to “1” from the defect list420, as shown, for example, in FIG. 4, stored in the memory at operation1330, and performs a verify-after-write process for blocks registered inthe sought entries at operation 1340.

If blocks registered in entries are blocks existing in a user data areaon the disk 100, according to certification results, the drive systemgenerates entries whose first state information 510, as shown, forexample, in FIG. 5, is set to a defect block state and whose secondstate information 530 is set to “0” if defects exist and deletescorresponding defect entries if no defect exists, at operation 1350.

If blocks registered in entries are blocks existing in a spare area,according to the certification results, the drive system generatesentries whose first state information 510 is set to an unavailable blockstate and whose second state information 530 is set to “0” if thereexist defects, and generates entries whose first state information 510is set to an available block state and whose second state information520 is set to “0” if there exists no defect, at operation 1360.

The drive system records a defect list 420 including the generatedentries on the disk 100, at operation 1370.

The certification method described above can be useful whenre-initialization is performed through a certification process.Moreover, even if a disk is not re-initialized, the certification methodcan be used when defect entries of a defect list are simply rearrangedin the middle of use of the disk.

The embodiments of the present invention can be written as computerprograms and can be implemented in general-use digital computers thatexecute the programs using a computer readable recording medium.Examples of the computer readable recording medium include magneticstorage media (e.g., ROM, floppy disks, hard disks, etc.), opticalrecording media (e.g., CD-ROMs, DVDs, etc.), and storage media such ascarrier waves (e.g., transmission through the internet). The computerreadable recording medium can also be distributed over network coupledcomputer systems so that the computer readable code is stored andexecuted in a distributed fashion. And the functional programs, codesand code segments for embodying the present invention may be easilydeducted by programmers in the art which the present invention belongsto.

As described above, according to embodiments of the present invention, are-initialization process can be quickly performed by using a method ofmanaging only defect information without a verify-after-write process.Furthermore, by a certification method according to embodiments of thepresent invention, defect information generated by performing quickre-initialization without certifying a disk can be effectivelyrearranged, thereby improving the performance of a drive system.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention. For example, any rewritable optical disc, suchas DVD-RW, DVD+RW, CD-RW and other high density disc, such as blue-raydisc (BD) and advanced optical disc (AOD) may be utilized. In addition,other storage media can also be utilized, including DVD, DVD-R, DVD-RAM,DVD-ROM, CD, CD-R, and CD-ROM, provided with a single recording layer ormultiple recording layers for recording data as long as the defectmanagement information is utilized in the manner as described withreference to FIG. 5, FIG. 6, FIGS. 7A-7B, FIGS. 8A-8B, FIGS. 9A-9B,FIGS. 10A-10B, FIGS. 11A-11B, FIGS. 10A-10B, FIGS. 11A-11B, FIGS.12A-12B and FIG. 13. In addition, a single spare area as shown in FIGS.7A-7B and multiple spare areas as shown in FIGS. 9A-9B and FIGS. 11A-11Bcan be fixed and/or flexible in sizes in designated areas of a data areaon an optical disk. Similarly, the system controller can be implementedas a chipset having firmware, or alternatively, a general or specialpurposed computer programmed to implement techniques and methods asdescribed with reference to FIG. 5, FIG. 6, FIGS. 7A-7B, FIGS. 8A-8B,FIGS. 9A-9B, FIGS. 10A-10B, FIGS. 11A-11B, FIGS. 10A-10B, FIGS. 11A-11B,FIGS. 12A-12B and FIG. 13. Accordingly, it is intended, therefore, thatthe present invention not be limited to the various example embodimentsdisclosed, but that the present invention includes all embodimentsfalling within the scope of the appended claims.

1. A method of determining whether defects exist in an informationstorage medium having a data area including a user data area forrecording data and a spare area for recording a replacement block toreplace a defect block occurring in the user data area, the methodcomprising: seeking a defect entry whose state information indicatesthat a defect block or a replacement block has been reinitializedwithout certification, from a defect list for managing the medium andincluding state information of the defect block and state information ofthe replacement block; and certifying the defect block or thereplacement block registered in the defect entry.
 2. The method asclaimed in claim 1, further comprising: deleting the defect entry whosestate information indicates that the defect block or the replacementblock has been re-initialized without certification from the defect listas a result of the certification.
 3. The method as claimed in claim 1,wherein state information indicating that a corresponding block is adefectable block is further included in the defect entry whose stateinformation indicates that the defect block or the replacement block hasbeen re-initialized without certification.
 4. The method as claimed inclaim 3, wherein the certifying comprises: if no defect exists in thedefectable block as a result of the certification of the defectableblock, deleting the defect entry from the defect list; and if a defectexists in the defectable block as the result of the certification of thedefectable block, generating a defect entry whose state informationindicates that the corresponding block is a defect block, wherein stateinformation indicating that the defect block or the replacement blockhas been re-initialized without certification is not set in the defectentry.
 5. The method as claimed in claim 1, wherein state informationindicating that a corresponding replacement block is an availablereplacement block or state information indicating that the correspondingreplacement block is an unavailable replacement block is furtherincluded in the defect entry whose state information indicates that thedefect block or the replacement block has been reinitialized withoutcertification.
 6. The method as claimed in claim 5, wherein thecertifying comprises: if no defect exists in the correspondingreplacement block as a result of the certification of the correspondingreplacement block, generating a defect entry whose state informationindicates that the corresponding replacement block is an availablereplacement block, wherein state information indicating that the defectblock or the replacement block has been re-initialized withoutcertification is not set in the defect entry; and if a defect exists inthe corresponding replacement block as the result of certification ofthe corresponding replacement block, generating a defect entry whosestate information indicates that the corresponding replacement block isan unavailable replacement block, wherein state information indicatingthat the defect block or the replacement block has been re-initializedwithout certification is not set in the defect entry.
 7. Arecording/reproducing apparatus comprising: a write/read unit to recorddata on an information storage medium and read data from the medium; anda control unit arranged to control the write/read unit to read a defectlist including state information of a defect block and state informationof a replacement block in order to manage the medium including a sparearea for recording the replacement block to replace the defect blockoccurring in a user data area on the medium, to seek a defect entrywhose state information indicates that the defect block or thereplacement block has been re-initialized without certification, and tocertify the defect block or the replacement block registered in thedefect entry.
 8. The apparatus as claimed in claim 7, wherein thecontrol unit deletes the defect entry whose state information indicatesthat the defect block or the replacement block has been re-initializedwithout certification from the defect list as a result of thecertification.
 9. The apparatus as claimed in claim 7, wherein stateinformation indicating that a corresponding block is a defectable blockis further included in the defect entry whose state informationindicates that the defect block or the replacement block has beenre-initialized without certification.
 10. The apparatus as claimed inclaim 9, wherein: if no defect exists in the defectable block as aresult of the certification of the defectable block, the control unitdeletes the defect entry from the defect list, and if a defect exists inthe defectable block as the result of the certification of thedefectable block, the control unit generates a defect entry whose stateinformation indicates that the corresponding block is a defect block,wherein state information indicating that the defect block or thereplacement block has been reinitialized without certification is notset in the defect entry.
 11. The apparatus as claimed in claim 7,wherein state information indicating that a corresponding replacementblock is an available replacement block or state information indicatingthat the corresponding replacement block is an unavailable replacementblock is further included in the defect entry whose state informationindicates that the defect block or the replacement block has beenre-initialized without certification.
 12. The apparatus as claimed inclaim 11, wherein: if no defect exists in the corresponding replacementblock as a result of the certification of the corresponding replacementblock, the controller generates a defect entry whose state informationindicates that the corresponding replacement block is an availablereplacement block, wherein state information indicating that the defectblock or the replacement block has been re-initialized withoutcertification is not set in the defect entry, and if a defect exists inthe corresponding replacement block as the result of the certificationof the corresponding replacement block, the controller generates adefect entry whose state information indicates that the correspondingreplacement block is an unavailable replacement block, wherein stateinformation indicating that the defect block or the replacement blockhas been re-initialized without certification is not set in the defectentry.
 13. An information storage medium, comprising: a lead-in areaprovided in an inner circumference; a lead-out area provided in an outercircumference; a data area disposed between the lead-in area and thelead-out area, including a user data area to record data and a sparearea to record a replacement block to replace a defect block occurringin the user data area; and a defect list provided in the lead-in area,including state information of a defect block and state information of areplacement block for defect management, wherein the defect block or thereplacement block registered in a defect entry whose state informationindicates that the defect block or the replacement block has beenre-initialized without certification is certified in a certificationoperation of the medium.
 14. The information storage medium as claimedin claim 13, wherein the defect entry whose state information indicatesthat the defect block or the replacement block has been re-initializedwithout certification is deleted from the defect list as a result of thecertification.
 15. An apparatus for recording/reproducing data on/froman information storage medium, comprising: a write/read unit whichrecords data on the information storage medium and reads recorded datafrom the information storage medium; a control unit which controls thewrite/read unit to record data on the information storage medium andread recorded data from the information storage medium, which allocatesa new spare area upon re-initialization and manages, via a defect list,state information of defect blocks in a user data area and stateinformation of replacement blocks in the new spare area on theinformation storage medium when the new spare area is allocated uponre-initialization, such that blocks having defect information areprovided with state information indicating that these blocks have beenre-initialized without certification.
 16. The apparatus as claimed inclaim 15, wherein the blocks having defect information are defect blocksor defectable blocks registered in the defect list indicating that thedefect blocks or defectable blocks have been re-initialized withoutcertification.
 17. The apparatus as claimed in claim 16, wherein thecontrol unit is further configured to: seek a defect entry from thedefect list whose state information indicates that a defect block or adefectable block has been re-initialized without certification; certifythe defect block or the defectable block registered in the defect entry,via a verify-after-write operation; and delete the defect entry whosestate information indicates that the defect block or the defectableblock has been reinitialized without certification from the defect listas a result of the certification.
 18. The apparatus as claimed in claim17, wherein the control unit is further configured to delete the defectentry from the defect list, if no defect exists in the defectable blockas a result of the certification of the defectable block, and togenerate a defect entry whose state information indicates that acorresponding block is a defect block, if a defect exists in thedefectable block as the result of the certification of the defectableblock, wherein state information indicating that the defect block or thedefectable block has been reinitialized without certification is not setin the defect entry.
 19. The apparatus as claimed in claim 17, whereinstate information indicating that a corresponding replacement block isan available replacement block, or state information indicating that thecorresponding replacement block is an unavailable replacement block isfurther included in the defect entry whose state information indicatesthat the defect block or the defectable block has been re-initializedwithout certification.
 20. The apparatus as claimed in claim 17,wherein: if no defect exists in a corresponding replacement block as aresult of the certification of the corresponding replacement block, thecontrol unit generates a defect entry whose state information indicatesthat the corresponding replacement block is an available replacementblock, wherein state information indicating that re-initializationwithout certification has been performed is not set in the defect entry,and if a defect exists in the corresponding replacement block as theresult of the certification of the corresponding replacement block, thecontrol unit generates a defect entry whose state information indicatesthat the corresponding replacement block is an unavailable replacementblock, wherein state information indicating that re-initializationwithout certification has been performed is not set in the defect entry.21. The apparatus as claimed in claim 17, wherein the control unit isconfigured to certify, via a verify-after-write operation, by: seekingone or more entries from the defect list whose state informationindicates that re-initialization has been performed; when blocksregistered in entries are blocks existing in the user data area on theinformation storage medium, generating entries whose state informationare set to a defect block state and indicate before re-initialization ifdefects exist, and if no defects exist, deleting corresponding defectentries from the defect list; when blocks registered in entries areblocks existing in the spare area on the information storage medium,generating entries whose state information are set to an unavailableblock state and indicate before re-initialization if defects exist, andif no defects exist, generating entries whose state information are setto an available block state and indicate before re-initialization; andrecord the defect list including generated entries on the informationstorage medium.
 22. A method of managing defects on an optical diskhaving a data area including a user data area for recording data and aspare area for recording a replacement block to replace a defect blockoccurring in the user data area, the method comprising: allocating a newspare area upon disk re-initialization; and managing, via a defect list,state information of defect blocks in the user data area and stateinformation of replacement blocks in the new spare area on the opticaldisk when the new spare area is allocated upon the diskre-initialization, such that blocks having defect information areprovided with state information indicating that these blocks have beenre-initialized without certification.
 23. The method as claimed in claim22, wherein the blocks having defect information are defect blocks ordefectable blocks registered in the defect list indicating that thedefect blocks or defectable blocks have been re-initialized withoutcertification.
 24. The method as claimed in claim 23, furthercomprising: seeking a defect entry from the defect list whose stateinformation indicates that a defect block or a defectable block has beenre-initialized without certification; performing certification of thedefect block or the defectable block registered in the defect entry, viaa verify-after-write operation; and deleting the defect entry whosestate information indicates that the defect block or the defectableblock has been re-initialized without certification from the defect listas a result of the certification.
 25. The method as claimed in claim 24,further comprising: deleting the defect entry from the defect list, ifno defect exists in the defectable block as a result of thecertification of the defectable block; and generating a defect entrywhose state information indicates that a corresponding block is a defectblock, if a defect exists in the defectable block as the result of thecertification of the defectable block, wherein state informationindicating that the defect block or the defectable block has beenre-initialized without certification is not set in the defect entry. 26.The method as claimed in claim 24, wherein state information indicatingthat a corresponding replacement block is an available replacementblock, or state information indicating that the correspondingreplacement block is an unavailable replacement block is furtherincluded in the defect entry whose state information indicates that thedefect block or the defectable block has been re-initialized withoutcertification.
 27. The method as claimed in claim 24, furthercomprising: if no defect exists in a corresponding replacement block asa result of the certification of the corresponding replacement block,generating a defect entry whose state information indicates that thecorresponding replacement block is an available replacement block,wherein state information indicating that re-initialization withoutcertification has been performed is not set in the defect entry, and ifa defect exists in the corresponding replacement block as the result ofthe certification of the corresponding replacement block, generating adefect entry whose state information indicates that the correspondingreplacement block is an unavailable replacement block, wherein stateinformation indicating that re-initialization without certification hasbeen performed is not set in the defect entry.
 28. The method as claimedin claim 24, wherein the certification is performed, via theverify-after-write operation, by: seeking one or more entries from thedefect list whose state information indicates that re-initialization hasbeen performed; when blocks registered in entries are blocks existing inthe user data area on the optical disk, generating entries whose stateinformation are set to a defect block state and indicate beforere-initialization if defects exist, and if no defects exist, deletingcorresponding defect entries from the defect list; when blocksregistered in entries are blocks existing in the spare area on theoptical disk, generating entries whose state information are set to anunavailable block state and indicate before re-initialization if defectsexist, and if no defects exist, generating entries whose stateinformation are set to an available block state and indicate beforere-initialization; and record the defect list including generatedentries on the optical disk.